/Engine/Source/Runtime/Engine/Classes/EditorFramework/AssetImportData.h
Replace the source files with the one provided. The MD5 hashes will be computed if they aren't set
void SetSourceFiles ( [TArray](API\Runtime\Core\Containers\TArray)< [FAssetImportInfo::FSourceFile](API\Runtime\Engine\EditorFramework\FAssetImportInfo\FSourceFile) > && SourceFiles )